More Efficient UV Lasers
By Erika Jonietz in Technology Review, January 4 2010
Electrical engineers in Debdeep Jena's lab at the University of Notre Dame have found a way to make two nitride semiconductors conduct electricity better, which may make them useful for building more effective ultraviolet (UV) lasers and light-emitting diodes (LEDs). These devices could enable a wide range of applications such as high-density optical data storage, water treatment, sterilization of medical equipment, UV-enabled security marks on credit cards and paper money, and biological imaging.
Nitride semiconductors such as aluminum gallium nitride and gallium nitride have the widest spectral range of band gaps--the energy required to move electrons through the material--among all semiconductors, ranging from the infrared through the visible and into the deep UV range. This makes them excellent for use in short-wavelength lasers and in LEDs for solid-state lighting, but it also makes it hard for engineers to design energy-efficient devices.